﻿/************************************************************************

   Extended Silverlight Toolkit

   Copyright (C) 2010-2012 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://extendedsilverlight.codeplex.com/license

   Please purchase a commercial version of this toolkit if you are using
   it in a commercial product. The commercial versions support the project,
   and also include more features for each control, priority support,
   source code, updates, removed watermark, and a proprietary license.

   Visit http://xceed.com and follow @datagrid on Twitter.

  **********************************************************************/

using System;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;

namespace Xceed.Silverlight.DataGrid
{
  internal sealed class ValidationErrorsObservableCollection<T> : ObservableCollection<T>
  {
    #region Constructor

    public ValidationErrorsObservableCollection()
    {
      m_batchOperation = new InhibitorFlag();
      m_batchOperation.PropertyChanged += new PropertyChangedEventHandler( this.OnBatchOperationChanged );
    }

    #endregion

    public IDisposable Batch()
    {
      return m_batchOperation.Set();
    }

    protected override void OnCollectionChanged( NotifyCollectionChangedEventArgs e )
    {
      if( m_batchOperation.IsSet )
      {
        m_collectionChangedSwallowed = true;
      }
      else
      {
        base.OnCollectionChanged( e );
      }
    }

    private void OnBatchOperationChanged( object sender, PropertyChangedEventArgs e )
    {
      if( !m_batchOperation.IsSet && m_collectionChangedSwallowed )
      {
        m_collectionChangedSwallowed = false;
        this.OnCollectionChanged( new NotifyCollectionChangedEventArgs( NotifyCollectionChangedAction.Reset ) );
      }
    }

    #region Private Fields

    private readonly InhibitorFlag m_batchOperation;
    private bool m_collectionChangedSwallowed; //false

    #endregion
  }
}
